Loyola University Chicago

Department of Biology

Erin M. O'Shaughnessey Project Description

Habitat Associations and Community Interactions of Non-Native Species in the Southern Basin of Lake Michigan


Non-native crayfishes, mollusks, and macrophytes can have large impacts on biodiversity and damage ecosystem services in freshwaters. In 2015 we discovered an established population of the globally widespread invader red swamp crayfish (Procambarus clarkii) in the North Shore Channel of the Chicago Area Waterway System. This population overlaps with a population of rusty crayfish (Faxonius rusticus), a previous invader that is widely distributed and usually the dominant crayfish species across the Great Lakes region. I studied the interactions between these two species while directly competing over shelter and food. In the field, each species was studied to determine the rate of predation in a channel with murky water, and a harbor with clear water. This overlapping population was discovered while sampling for crayfish species throughout the Chicago region. Crayfish are poorly sampled in the Great Lakes Region, leaving large gaps in knowledge of native and non-native crayfish distribution. I examined the role that artificial habitat and anthropogenic changes have on crayfish distribution and created an updated distribution of crayfishes in the Chicago region. I also studied the relationship between the arrangement of anthropogenic habitat to non-burrowing mollusks and macrophytes. The density and species composition were compared between habitat types. I aimed to study the role that human habitats play in the distribution of non-native and native crayfish, mollusks, and macrophytes.


This research was funded by Illinois Department of Natural Resources. Thank you to my advisor Dr. Reuben Keller and my committee members Dr. Martin Berg and Dr. Tim Hoellein for their time and comments on my thesis. Thanks to Dr. Victoria Prescott for the many hours spent helping with data analysis and R, and at happy hours. Thanks also to Jenny Par and Deirdre Turner at Loyola University Chicago for their help in the lab and identifying mollusk samples. Thank you to Rachel Egly, Trent Henry, Jon Brenner, John Zink, Gabrielle Habeeb, Bridie Hulsebsoch, and Shehla Chowdhury for their help in the field and lab. Finally, thanks to my family and friends for their support during field work and the writing process.


Erin O’Shaughnessey was born and raised in Mason, Ohio. She graduated from The Ohio State University in May 2016 with a Bachelor of Science in Environmental Science and a specialization in Water Science. O’Shaughnessey started the Masters of Science program at Loyola University Chicago in June 2016. In January 2018, she was awarded an Advanced Scientific Dive Training Grant from the Women’s Diver Hall of Fame.


Dr. Reuben Keller

Dr. Martin Berg

Dr. Timothy  Hoellein